Shenzhen.

Yes, the levels can be selected just as the higher-tier Hiby OS models, but the DSP effects are a bit more “realistic” on those higher models. This is likely due to better CPU on those models, as the AP80 Pro (and the likes) are budget-oriented and has rather basic CPUs inside.

AP80 Pro is very good, and really ticks a lot of boxes. If you plan on upgrading, take a look at the Tempotec V6. Has the Hiby OS, and also sounds noticeably better across the board with a larger display and Android. Battery life is pretty good as well.

From the article: “However, the implementation [of MSEB] here on the AP80 Pro isn’t as good as the one found on Hiby R6 2020, or even the Hiby R3 Pro Saber. Both of those had a more convincing tweak to the sound whereas on the AP80 Pro it feels like you’re just using a multi-band EQ and never really have the same control on shaping the sound.”

I have the AP80 Pro, you may not have noticed, but in the MSEB settings (the little gear icon found after clicking on MSEB, not in the Play Settings), you can adjust what “level” of MSEB you want to use, either ‘Fine Tuning’ (lowest), ‘Middling’ (middle), or ‘Excessive’ (highest). It is automatically set on the lowest ‘Fine tuning’ setting, but if you set it to ‘Middling’ or ‘Excessive’ it changes/shapes the sound much more noticeably. It usually cuts the volume a little with MSEB turned on.

(However, I have not used MSEB on any other player, so I do not know how it compares to other players with it.)

I am not one to use an Equalizer on any player, ever, except maybe presets very occasionally, so I did not use MSEB at all much at first, but now find it quite enjoyable to use on occasional recordings or headphones that need a little tweaking. It is much easier to use than a naked parametric equalizer for the novice (like myself).

The AP80 Pro is a great entry level unit. It’s the nicest DAP I’ve ever used, had it about a year or so, and will probably upgrade to a slightly better model in a couple years. Before this I stuck to using sub $50 DAPs or smartphone and some nice budgety amps. My only issues are the smallish screen (though I love the size, it’s a tradeoff) and a bigger battery would be nice, though it’s been quite adequate. Also I don’t like how HibyOS software doesn’t let you browse by ‘Album Artist’ or just by even a few more tags in the files, so I usually just browse files by Folders. (I got spoiled using Sansa Clip players with RoxkBox for several years, so many options in that OS!) But I am hooked on the Hidizs’ stellar sound, the solid build quality and the player has introduced me to the world of balanced headphones.

I think it’s best to contact Hidizs, but if it’s the glass on the back-panel then you can get some “bonding glue” from hardware stores (metal-glass bonding glues). For your purpose you can probably just get by with relatively low-strength ones.